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BURGLAR ALARM. No. 284,012. Patented Aug. 28,1883.

@ i INVENTOR ATTORNEYS.

v the attachment of alarms to door-knobs, and

UNITED STATES FREDERICK D. HILL, OF'NEl/V YORK,

PATENT OFFICE.

N. Y., ASSIGNOR OF TVVO-THIRDS TO GEORGE WV. NELSON AND JACOB S. FREER, OF SAME PLACE.

BURGLAR-ALARM.

SPECIFICATION forming part of Letters Patent No. 284,012, dated August 28, 1883.

Application filed May 22, 1883. (ModeL) To all whom it may concern Be it known that'I, FREDERICK D. HILL, of the city, county, and State of New York, have invented a new and useful Improvement in Burglar-Alarms, of which the following is a full, clear, and exact description.

Reference is to be had to the accompanying drawings, forming a part of this specification, in which similar letters of reference indicate corresponding parts in all the figures.

Figure 1 is a side elevation, partly in sec-.

tion, of my improvement. Fig. 2 is a front elevation of the same, partly in section and part being broken away. Fig. 3 isa sectional plan view of the same, taken through the line a; as, Fig. 1.

The object of this invention is to facilitate promote certainty in the operation of such alarms.

The invention consists in a burglar-alarm constructed with a spring-clamp connected with a bar jointed to a suspended frame carrying a clock-work and gong, and a sliding rod provided with a spring, and having fingers to engagewith the escapementanchor, and a catch attached to the suspending-bar, whereby the alarm can be readily suspended from a door-knob, and will be sprung by the movement of the said knob, as will be hereinafter fully described.

A represents a small frame, to which is atelastic or is held up b a s rin G con- 7 I D) 7 nected with it and with the said bar D. The arm F is so formed as to fit against the lower side of an ordinary door-knob, so that the bar D will be securely clamped to the said doorknob, and when the said knob is turned the said. bar D will be carried with it.

With the escapement-anchor H of the clockwork B is rigidly connected the bell-hammer bell-hammer I, rigidly connectedwiththe said escapement-anchor H, so that the rod J ,when raised, will press the said escapement-anchor against the escapement-wheel of the clockwork B, and thus lock the said clock-work.

To the upper end of the rod J is attached, or upon it is formed, a finger, M, which projects inward to rest when the said rod J is ,raised to lock the clock-work upon a catch,

N, attached to the bar D.

Upon the rod J is placed a spiral or other shaped spring, 0, the lower end of which rests upon a collar or pin, 1?, attached to the said rod J, and its upper end rests against a guide, Q, attached to the frame A, so that the said spring will be compressed when the said rod J is raised and hung upon the catch. N.

If desired, the catch N may be covered by a cap, sliding upon the upper part of the bar D, to prevent the finger M from being accidentally pushed off the catch Nwhen winding up the spring of the clock-work or when applying the alarm to the doorknob. With this construction,when the door-knob is turned the bar D will be turned with it, while the frame A and its attachments will be held vertical by gravity, causing a movement in the joint connecting the bar D and frame A,which movement carries the finger M off the catch N, and allows the rod J to be thrown down ward by the elasticity of the spring '0, releasing the clock-work and allowing the hammer have before been attached to door-knobs, in

which the turning of the knob throws out of line the joint of a pendulum containing the alarmbelland clock-work to sound the same, thus freeing the means of restraining the clock and allowing it to sound the alarm, and I do not claim the same, broadly, as my invention.

Having thus described my invention, I claim as new and desireto secure by Letters Patent- 1. The combination, with an alarm-gong, clock-work for sounding it, an escapement in the'clock, andua jointed connection adapted to suspend the alarm upon a door-knob, the portion above the joint being provided with a fixed catch, of avertically-sliding rod, a spring forcing said rod downward, a finger at its top to rest on said fixed catch, and a finger at its lower end adapted to hold the escapement engaged, whereby the turning of the knob will disengage the catch from the upper finger, freeing it to be forced loose from the escapement, and allowing the gong to be sounded, as described.

2. In a burglar-alarm, the combination, with the suspending-bar D, carrying the operating parts of the mechanism, of the forked arm E and the spring-arm F, substantially as herein shown and described, whereby the alarm can be readily secured to and suspended from a door-knob, as set forth. I

FREDERICK D. HILL. Witnesses:

J AMES T. GRAHAM, EDGAR TATE. 

